The present invention relates to a device for protecting a turntable shaft of a microwave oven, and particularly to a device for preventing a turntable shaft formed out of resinous material from fusing when the microwave oven is operating.
In the conventional microwave oven, as shown in FIG. 1, the turntable 12 is installed on the base plate 11 of the heating chamber in the main body of the microwave oven. The food to be cooked is put on the turntable and heated uniformly by the microwave. The rotating shaft 13 which is fixed to the turntable 12 and mounted rotatably on the base plate 11 of the heating chamber is normally made from resinous material.
When using the conventional device, problems arise when the shaft 13 made of resinous material is heated by the microwave during the heating of the food. The problems are that the shaft 13 fuses, or sparks occur around the shaft 13 of the base plate 11 in the heating chamber, and the like.
In the conventional microwave oven, no device for protecting the turntable shaft 13 has been used, or a metal intercepting plate 14 has been fixed around the shaft 13 to prevent microwaves from concentrating in the zone of the shaft 13.
However, since the characteristics of the microwaves have not been considered up to now, the intercepting plate 14 has been shaped in a simple cylindrical form making it impossible to fundamentally eliminate the concentrating of microwaves in the zone around the shaft 13. Also a defect in the intercepting plates causes the intercepting plate 14 to perform unsatisfactorily the function of preventing the microwave from being absorbed into the shaft 13. Therefore, to avoid the problems, the conventional microwave oven requires that the shaft 13 be molded out of expensive resinous material, and thereby increasing the cost of the products.